There are two different sized guitarra, Lisboa and Coimbra, the strings gauge and tuning is as follows:
Lisbon (Lisboa) Tuning) 440mm scale
1st, 2nd and 8th strings-- .009" wire string. Tuned to B
3rd, 4th and 10th strings--.010" wire strings. Tuned to A (This A = 440 Hz)
5th, 6th strings-- .013" wire strings. Tuned to E
7th string --.020" wound. Tuned an octave below the 8th string (B)
9th string --.024" wound. Tuned an octave below 10th string (A)
11th string -- .034" wound. Tuned to D ( like the 4th string on the Acoustic Guitar)
12th string -- .018" wound. Tuned an octave above the 11th string (D)
Coimbra Tuning 470mm scale
1st, 2nd and 8th strings-- .011" wire string. Tuned to A ( This A = 440 Hz)
3rd, 4th and 10th strings--.012" wire strings. Tuned to G
5th, 6th strings-- .015" wire strings. Tuned to D
7th string --.022" wound. Tuned an octave below the 8th string (A)
9th string --.024" wound. Tuned an octave below 10th string (G)
11th string -- .036" wound. Tuned to C (like the 5th string, 3rd fret on the acoustic guitar)
12th string -- .019" wound. Tuned an octave above the 11th string (C )
The tuning is unusual and the playing method also. They are normally played with by alternate picking with the thumb and forefinger.
Roger
"Do, or do not; there is no try"